Your First Stop for HVAC Equipment. Now on the Web
space space space
space Products space
space Fabric air duct space
space Installations space
space Photos space
space Make-up air space
space Questionnaire space


space About us space

Contact Us:

Pavesi & Associates, Inc.
1556 White Ash Dr.
Carmel, IN 46033

(P) 317-844-4783
(F) 317-846-7907


Make-Up Air System Installation Instructions

Installation of MUA Unit Housing

1. Locate the height of the make-up air unit in reference to obstructions downstream where the fabric air distribution duct is to be suspended.

  Ex. If there is an obstruction in the path, either remove/relocate the obstruction or move the MUA unit so that the MUA discharge clears the obstruction. For optimum system performance and product life, it is important that the fabric air distribution duct run straight without any kinks or bends.

2. After determining the mounting height of the MUA unit, you then must decide whether you want to suspend the unit with 1/2" threaded rod from the top four corners of the MUA unit or by running angle iron or heavy wall channel along the bottom on both ends of the MUA unit supported from the roof trusses with threaded rod, angle iron, or heavy wall channel. If you choose to suspend the MUA unit from the top, drill 1/2" holes in each corner 1" in from each side. Using either 3" x 3" x 1/4" angle iron or heavy wall channel spanning the trusses, determine the length of 1/2" threaded rod, angle iron, or heavy wall channel required to hang the unit.

3. The 1/2" threaded rod is passed through the hole in the top of the unit and secured with a small 2" square reinforcing pad (10 gauge steel), double 1/2" nuts on the inside and one 1/2" nut on the outside. The other end of the 1/2" threaded rod passes through the angle iron or heavy wall channel installed at the roof level and is similarly secured. If you choose to place angle iron or heavy wall channel along the bottom of the unit, the same fastening procedures apply.

Note: Threaded rod, angle iron rod, heavy wall channel, reinforcing pads and hardware supplied by others.

Installation of Airstream Silencer

1. The silencer connects to the Jetstream MUA unit by sliding the end of the silencer with the flow straightener blades over the venturi ring. The silencer should be suspended with "half saddles" (half saddle by others) on both ends. The half saddles are normally supported with 1/2" threaded rod, angle iron or heavy wall channel.

2. The silencer should be attached to the MUA unit with sheet metal screws equally spaced. The option is yours to either screw from the outside of the silencer in or from the inside out. If you choose to screw from the outside in be absolutely sure there is sufficient space between the screws and the fan blades as the fan blades will deflect when the propeller is rotating.

Fabric Air Distribution Duct

1. The fabric ducts are suspended from aircraft-type cable. Attach the aircraft cable(s) to the anchor point(s), e.g. eye bolts. Thread aircraft cable through the eyebolt and secure with two cable clamps. Run aircraft cable to a fixed point and secure with two cable clamps. Adjust the turnbuckle so that the aircraft cable is taunt. Be careful not to over tighten the aircraft cable.

2. After the aircraft cable has been installed, it may be necessary to secure the cable from above to support the weight of the fabric air duct and insure that all of the ducts are level. This can be accomplished by dropping jack chain (supplied by others) secured from the roof truss to the aircraft cable and using an S-hook to fasten. The length of the chain should be the same as the distance of the discharge section from the roof truss. The spacing of the chain usually works out to about 30'-40' centers depending upon the diameter and type of fabric duct. Observation when all of the ducts are installed will indicate whether additional chains are required.

Sheet Metal Transition (Wall Sleeve)

1. A sheet metal transition (supplied by others) with a 1 1/2" flange turned out on one end is fastened to the intake side of the MUA unit. The other end of the transition should have a raw edge, i.e. no flange. The length of the transition should be sufficient to position the wall sleeve even to the outside wall edge. For efficiency of airflow, we recommend that the sheet metal transition not protude beyond the exterior wall opening into the hood. It has been our practice to allow this end of the transition to "free float" rather than attach it firmly to the wall.

Intake Duct

1. The optional intake duct is available in different drop lengths. The intake duct is designed to drop through the flat roof curb and connect to the optional intake plenum with a "Nexus" type fitting.

Intake Plenum

1. The optional intake plenum is designed to connect the intake duct to the Multi-Jet Jetstream Unheated MUA unit with a "Nexus" type fitting. The MUA unit comes with a special flange added on the intake side to facilitate installation to the intake plenum.